PROJECT SUMMARY/ABSTRACT Many children with hearing loss (CHL) now receive early intervention within the first few months of life. Even with early intervention, however, some CHL with hearing aids do not reach their full developmental potential. Challenges are compounded in learning and social environments because most listening environments are characterized by background noise. CHL experience significantly greater difficulty than children with normal hearing (CNH) with understanding speech in noisy situations. CHL who wear hearing aids are an under- studied population, leading to substantial gaps in our knowledge regarding the underlying mechanisms for their speech in noise deficits. A limited understanding of the mechanisms for speech recognition in noise hinders the development of targeted intervention strategies to reduce these deficits. The current proposal will identify factors that underlie variability in speech recognition in noise in school-age CHL who use hearing aids. This proposal is based on the premise that selective attention, working memory, and language support processes that are crucial for speech recognition in noise. The current proposal seeks to test the hypothesis that CHL with better selective attention, working memory, and language abilities will have stronger spectral resolution, perceptual weighting for speech, and less susceptibility to informational masking. Advantages in these skills will be associated with better speech understanding in noise. Three specific aims are proposed: Aim 1. Examine the effects of selective attention, working memory, and spectral resolution on speech recognition in noise. Aim 2. Characterize the effects of selective attention and language on perceptual weighting for speech in noise. Aim 3. Evaluate selective attention as a predictor of speech recognition in speech maskers. In Aim 1, we will examine measures of selective attention, working memory, and spectral resolution on speech recognition in noise for CNH and CHL. We predict that selective attention and working memory support spectral resolution in children, which in turn support speech recognition in noise. In Aim 2, perceptual weighting functions will be measured for speech stimuli that vary in linguistic complexity. We predict that CNH and CHL with stronger selective attention, working memory, and language skills will have perceptual weights concentrated in mid-frequency bands, reflecting mature and selective listening that is less susceptible to noise. In Aim 3, we will assess the effects of selective attention on speech recognition with speech maskers that produce informational masking. We predict that CNH and CHL who have stronger selective attention skills will have less susceptibility to informational masking than peers with poorer skills, but that this effect is mediated by the child's language and working memory abilities. The data generated from this proposal will inform theoretical models regarding speech recognition in CNH and CHL. The proposed studies will also provide empirical evidence for the development of individualized strategies for prescribing hearing aids for children that are based on the child's individual cognitive and linguistic skills.